These areas are designated as medicinal plant protection zones under the 1999 Thai Traditional Medicine Promotion and Protection Act. People are not allowed to destroy any medicinal plant in such areas. Anyone who violates the law can be punished under Natural Resources and Environment Ministry regulations.

Previously, the Public Health Ministry designated 12 areas across country as protection zones for medicinal plants.

Public Health Minster Witthaya Buranasiri said: "People stole these medicinal plants from the forest to produce a drug that helps overcome sexual dysfunction.

"These medicinal plants are very important for drug development to cure diseases in future. We need to protect these plants," he said.

In a bid to reduce importation of drugs, the government has a policy to promote the use of traditional medicine produced from local plants to treat patients in hospitals. The government also promotes supplements and cosmetic products made from herbal plants.

The ministry's Development of Thai Traditional and Alternative Medicine Department conducted a project to plant medicinal trees in damaged forest areas and to build understanding among members of the public about protecting endangered herbal plants.